Regarding whether it is likely or not that a terrorist organization would implement the use of CBRN weapons, I think it is something that the United States cannot ever rule out of the equation. The conflict/war with terrorism all around the world is an ever-evolving structure with developing and unconventional warfare tactics being used in part of the terror organizations. As described by Vicar, Terrorism is It is a deliberate, preconceived use of force or threat of force, usually often focused on not involved persons to trigger a fear, through which terrorists’ political, ideological and religious requirements are to be met. In a global war, everyone is a target of terrorists, especially unprotected civilians, as they are the easiest targets.” (Vicar, 2011, pg. 21) If terror organizations think that current tactics are not inciting fear in the people of the United States, then it is quite possible that they attempt to carry out a large scale CBRN attack on US soil. Koblentz writes during is study, “A 2007 survey found that 51% of biologists believed that there would a bioterrorism incident somewhere in the world within the next five years. The Graham-Talent Commission also concluded that terrorists are more likely to be able to obtain and use a biological weapon than a nuclear weapon.” (Koblentz, 2011, pg. 502)
Determing which area would be hit first or at all, the odds are more lkely of the introduction of a CBRN attack on US soldiers downrange in the fight. While maybe not a large exposure, there could be test sites to see the effects of it that do not effect the civilan populace there in their own country. If that produces the results desired, then it would be mimicked all around that area and eventually make its way into the US. Similar to the introduction of peroxide based explosives(TATP/HMTD) and home made explosives(HME)
Terrorism is meant to cause fear and destruction, a realist has to understand that there is a real possibility to have the worst types of attacks on both US and foreign soil because the enemy is always looking at ways to advance their tactics. Unconventional warfare is the main tactic in our current adversaries.
RESOURCES:
Koblentz, G. D. (2011). Predicting peril or the peril of prediction? assessing the risk of CBRN terrorism. Terrorism and Political Violence, 23(4), 501-520. doi:10.1080/09546553.2011.575487
Vicar, D., & Vicar, R. (2011). CBRN TERRORISM: A CONTRIBUTION TO THE ANALYSIS OF RISKS. Journal of Defense Resources Management, 2(2), 21-28. Retrieved from http://search.proquest.com.ezproxy2.apus.edu/docview/1348605111?accountid=8289